MathGroup Archive 1993

[Date Index] [Thread Index] [Author Index]

Search the Archive

New User Question About NDSolve

  • To: mathgroup at
  • Subject: New User Question About NDSolve
  • From: Jay Maddux <jrm5c at>
  • Date: Wed, 1 Sep 1993 05:27:34 GMT

  I am trying to solve a simple heat-flow problem using the NDSolve routine.
The problem is for a one-dimensional, uniformly heated rod, so the equation
I am using is:  t''[x] == C1 (constant)

  The boundary conditions are: t[0] == C2
                               t'[1] == C3*t[1]

  This equation can easily be solved by hand (t[x] = Ax^2 + Bx + C), but
I would like to add additional terms if I can get the simplified version
to work with the NDSolve routine.

  The error message I get is:
      "NDSolve::ndinn: Initial condition t'[0.] is not a number."

  The routine works if I do give a value for t'[0], but this is not a number 
that I can really determine a priori.

  The second boundary condition would seem to require an iterative method to
solve for t[x], so maybe this is the problem ?

  I apologize if I have overlooked something obvious here, but I'd appreciate 
any help I can get.

jrm5c at

  • Prev by Date: conditional limits
  • Next by Date: ToolTool
  • Previous by thread: Re: conditional limits
  • Next by thread: ToolTool